diff --git a/reactos/lib/sdk/crt/crt.rbuild b/reactos/lib/sdk/crt/crt.rbuild
index 16a9ce8b98e..d1be14e9c6a 100644
--- a/reactos/lib/sdk/crt/crt.rbuild
+++ b/reactos/lib/sdk/crt/crt.rbuild
@@ -172,6 +172,7 @@
 				<file>floor.S</file>
 				<file>floorf.S</file>
 				<file>fmod.S</file>
+				<file>fmodf.S</file>
 				<file>ldexp.S</file>
 				<file>log.S</file>
 				<file>log10.S</file>
diff --git a/reactos/lib/sdk/crt/math/amd64/fmodf.S b/reactos/lib/sdk/crt/math/amd64/fmodf.S
new file mode 100644
index 00000000000..966ceffec40
--- /dev/null
+++ b/reactos/lib/sdk/crt/math/amd64/fmodf.S
@@ -0,0 +1,21 @@
+/*
+ * COPYRIGHT:         See COPYING in the top level directory
+ * PROJECT:           ReactOS system libraries
+ * PURPOSE:           Implementation of fmodf
+ * FILE:              lib/sdk/crt/math/amd64/fmodf.S
+ * PROGRAMMER:        Timo Kreuzer (timo.kreuzer@reactos.org)
+ */
+
+/* INCLUDES ******************************************************************/
+
+#include <ndk/amd64/asm.h>
+#include <ndk/amd64/asmmacro.S>
+
+.intel_syntax noprefix
+
+
+.proc fmodf
+    UNIMPLEMENTED fmodf
+    ret
+
+.endproc